Sir Cyril Norman Hinshelwood, a British physical chemist who shed light on how chemicals react, was born 101 years ago on this day. Hinshelwood, a professor at Oxford University, studied the decomposition of solid explosives by monitoring the gases they released, and found that even simple decompositions occur in stages. He later explained "chain reactions," in which activated molecules initiate a series of independent reactions.

Hinshelwood's 1926 work, "Kinetics of Chemical Change," became a classic and won him a share of the 1956 Nobel Prize in chemistry, along with Russian chemist Nikolay Semenov. Hinshelwood also studied how various nutrients, trace elements, and toxic substances influence the chemical reactions that occur during bacterial growth, publishing more than 100 papers on this subject as well. He died in 1967.